1. Field of the Invention
The invention relates to a portable information terminal such as a portable telephone or portable personal computer, which is portable and capable of communication.
2. Related Art
There has been rapid growth in the use of cellular telephone and PHS telephones (Japan's Personal Handyphone System), to the extent that virtually everyone will have his or her own telephone. With this growth there have been advancements in the sophistication of functions provided, and an increase in the speed of communication, so that whereas portable telephones were limited to voice communication, it has become possible to exchange image information as well. By doing this, it is possible to use a pair of portable telephones as television telephones, which enable observation of a screen while making a call.
The above-noted applies as well to a compact portable computer having a communication function. The present invention, unless otherwise noted herein, shall collectively refer to these devices as portable information terminals.
In this type of portable information terminal, by the very fact that it is portable, it is at risk of being stolen or used without permission. Under these conditions, if a person uses a portable information terminal without permission, the proper owner is billed for the telephone charges. Additionally, internal mail software can be used to send mail as if it were being sent by the rightful owner, and to improperly read stored mail intended for the rightful owner of the portable information terminal.
From the standpoint of security, there is prior art for verification of the proper identity of the user. For example, in the Japanese unexamined Patent Publication (KOKAI) No. 6-309448, there is disclosure of technology for using a retinal pattern or fingerprint to identify a proper user.
FIG. 12 to FIG. 14 show the technology disclosed in the above-noted Japanese unexamined Patent Publication. As shown in FIG. 12, when identifying the face of a proper user 10, a light path is formed via first lens 11, a first mirror 12, and a second lens 13, and image information of a face 10 is formed at an imaging element 14 disposed at the focal point of the second lens 13. When checking a fingerprint to see if it is of the proper user, the image of the tip of a finger that is pressed up against one surface of a fingerprint prism 16 strikes the second lens 13 via a fingerprint mirror 18, and is formed as an image on the imaging element 14. The fingerprint mirror 18 rotates through an angle of 90° about a pivot 19, and in the condition in which fingerprint is being checked, light rays reflected from the first mirror 12 are blocked, so that they do not strike the second lens 13. According to this optics system, it is possible to select verification of either the face 10 or the finger 17 of the subject.
In FIG. 13, in which elements the same as in FIG. 12 are assigned the same reference numerals, the first mirror 12 is movable, the movement position of which being used to perform switching of the optical image of either the face 10 or the finger 17, the light from which is caused to strike the second lens 13. According this optics system, it is possible to verify the proper user by selectively verifying either the face 10 or the finger 17.
In FIG. 14, the imaging element 14 can be rotated so as to be disposed at either a first rotational position or a second rotational position, and the second lens 13 moves along the light axis of the imaging element 14 in concert with this rotation. When the imaging element is positioned at the first position, a second mirror 21 forms an image of the finger 17 onto the imaging element 14, and when the imaging element 14 is positioned at the second position, the first mirror 12 forms an image of the face 10 on the imaging element 14. In the Japanese unexamined Patent Publication No. 63-272249, there is disclosure of technology whereby verification of identity is done by reading a face using an imaging element. In this technology, because verification is possible using the face, without using a fingerprint, the system is perceived by the subject as being easy to use.
In the technology disclosed in the Japanese unexamined Patent Publication (KOKAI) No. 6-309448, the optical images of the face 10 and the finger 17 are switched so as to use these images to identify a user. Therefore, compared the technology disclosed in the Japanese unexamined Patent Publication No. 63-272249, in which a face is read by an imaging element to perform verification, there is the advantage of being able to perform verification by means of fingerprint, in cases such as when the subject is wearing glasses or is disguised.
As shown in FIG. 12 to FIG. 14, however, in the technology disclosed in the Japanese unexamined Patent Publication (KOKAI) No. 6-309448, the use of a mirror is required. Although a mirror having a reflective coating on the rear surface is inexpensive, with this type of mirror reflections occur not only at the rear surface, but at the front surface as well. For this reason, in order to achieve a highly accurate image usable for verification of a fingerprint or a face, it is necessary to coat the front surface of the mirror, so as to prevent double reflections. This special type of mirror, however, is expensive, and the coated front surface of the mirror is exposed to the outside, so that it can be damaged. If the mirror coating becomes damaged, there is the problem of not being able to reliably obtain a highly accurate image of a face or fingerprint.
When performing verification using both a face and a fingerprint, it is necessary to provide reference patterns for both images, thereby adding the problem of an increase in the memory capacity for storing the reference patterns.
Accordingly, it is an object of the present invention to provide a portable information terminal, which, without using a mirror, uses a single imaging element and enables simple setting of two different subject positions.
It is a further object of the present invention to provide a portable information terminal, which, without using a mirror, uses a single imaging element to perform verification identity, utilizing a part other than the face.